Purine nucleoside antimetabolites, such as clofarabine, are effective antileukemic agents. However, their effectiveness depends on an initial activation step in which they are monophosphorylated by deoxycytidine kinase (dCK). Some purine nucleoside antimetabolites and their monophosphate derivatives are exported by the ABC transporter ABCG2. Because clofarabine is a dCK substrate, and we show s...

Thymidine phosphorylase (dThdPase) is an enzyme involved in pyrimidine nucleoside metabolism. However, little is known about its physiological functions. We previously purified dThdPase from human placenta, isolated a complementary DNA clone for this enzyme, and sequenced it. There was complete sequence identity between 120 amino acids of human dThdPase and the sequence of platelet-derived endo...

To evaluate the safety of regimens containing calcineurin inhibitors (CNI), proliferation signal inhibitors (TOR-I) and antimetabolites, we conducted a meta-analysis of randomized clinical trials (RCTs) and observational studies. A total of 4,960 citations were identified in our electronic search and 14 additional articles were identified through hand searching. Forty-eight articles (11,432 par...

AIM To evaluate the combined phacoemulsification with acrylic intraocular lens implantation and trabeculectomy with releasable sutures, without the use of antimetabolites, performed by one surgeon. METHODS A retrospective analysis was performed on 251 eyes of 198 patients after a combined phaco/trabeculectomy procedure, followed up for an average of 16 months for vision, intraocular pressure ...

Genome sequences of Plasmodium falciparum allow for global analysis of drug responses to antimalarial agents. It was of interest to learn how DNA microarrays may be used to study drug action in malaria parasites. In one large, tightly controlled study involving 123 microarray hybridizations between cDNA from isogenic drug-sensitive and drug-resistant parasites, a lethal antifolate (WR99210) fai...

The discovery last year that 3-methylaspartic acid (P-methylaspartic acid) is a natural metabolite formed by isomerization of glutamic acid through the intervention of a vitamin-Blz-containing coenzyme (1) suggests a new relationship of this vitamin to thymine biosynthesis. Thus, carbamylation of 3-methylaspartic acid would yield 3-methylureidosuccinic acid, which, by ring closure and deoxyribo...

Lung, prostate, and stomach cancer are the most prevalent cancers among males. Breast, colon, cervical women. The literature also shows that patients suffering from increasing constantly, hence number of different chemotherapy treatments administered is increasing. main objective this review article to summarize effect age on half-life some antineoplastic drugs belonging category Topoisomerase ...

Various examples of oxidation of purine molecules in positions 8 and 2 by xanthine oxidase have been reported. The conversions of the natural purine substrates, xanthine and hypoxanthine to uric acid (I) and of adenine to 2,8-dihydroxy-6-aminopurine, are well known. The oxidation of the purine antimetabolites, 6-mercaptopurine to 6-thiouric acid (2)) 2,6-diaminopurine to 2,6-diamino-6-hydroxy p...

The mitotic cell selection procedure for cell cycle anal ysis was utilized with Chinese hamster ovary fibroblasts to determine the transition points in G,, i.e., the age in G, at which cells become refractory to drug-induced progres sion blockade, for several cancer Chemotherapeutic agents and antimetabolites over a 1000-fold concentration range. The G transition points for five anticancer drug...

INTRODUCTION We describe a patient with corneal and scleral dellen, which occurred after an uneventful pterygium excision without adjunctive therapy and a subsequent febrile episode. CASE REPORT A 43-year-old woman presented with a history of recurrent irritation in her right eye and a diagnosis of pterygium. The pterygium was excised under local anesthesia with the bare scleral technique and...